sdio.c

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/*
 *  linux/drivers/mmc/sdio.c
 *
 *  Copyright 2006-2007 Pierre Ossman
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/err.h>
#include <linux/pm_runtime.h>

#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_func.h>
#include <linux/mmc/sdio_ids.h>

#include "core.h"
#include "bus.h"
#include "sd.h"
#include "sdio_bus.h"
#include "mmc_ops.h"
#include "sd_ops.h"
#include "sdio_ops.h"
#include "sdio_cis.h"

static int sdio_read_fbr(struct sdio_func *func)
{
    int ret;
    unsigned char data;

    if (mmc_card_nonstd_func_interface(func->card)) {
        func->class = SDIO_CLASS_NONE;
        return 0;
    }

    ret = mmc_io_rw_direct(func->card, 0, 0,
        SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF, 0, &data);
    if (ret)
        goto out;

    data &= 0x0f;

    if (data == 0x0f) {
        ret = mmc_io_rw_direct(func->card, 0, 0,
            SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF_EXT, 0, &data);
        if (ret)
            goto out;
    }

    func->class = data;

out:
    return ret;
}

static int sdio_init_func(struct mmc_card *card, unsigned int fn)
{
    int ret;
    struct sdio_func *func;

    BUG_ON(fn > SDIO_MAX_FUNCS);

    func = sdio_alloc_func(card);
    if (IS_ERR(func))
        return PTR_ERR(func);

    func->num = fn;

    if (!(card->quirks & MMC_QUIRK_NONSTD_SDIO)) {
        ret = sdio_read_fbr(func);
        if (ret)
            goto fail;

        ret = sdio_read_func_cis(func);
        if (ret)
            goto fail;
    } else {
        func->vendor = func->card->cis.vendor;
        func->device = func->card->cis.device;
        func->max_blksize = func->card->cis.blksize;
    }

    card->sdio_func[fn - 1] = func;

    return 0;

fail:
    /*
     * It is okay to remove the function here even though we hold
     * the host lock as we haven't registered the device yet.
     */
    sdio_remove_func(func);
    return ret;
}

static int sdio_read_cccr(struct mmc_card *card, u32 ocr)
{
    int ret;
    int cccr_vsn;
    int uhs = ocr & R4_18V_PRESENT;
    unsigned char data;
    unsigned char speed;

    memset(&card->cccr, 0, sizeof(struct sdio_cccr));

    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CCCR, 0, &data);
    if (ret)
        goto out;

    cccr_vsn = data & 0x0f;

    if (cccr_vsn > SDIO_CCCR_REV_3_00) {
        pr_err("%s: unrecognised CCCR structure version %d\n",
            mmc_hostname(card->host), cccr_vsn);
        return -EINVAL;
    }

    card->cccr.sdio_vsn = (data & 0xf0) >> 4;

    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CAPS, 0, &data);
    if (ret)
        goto out;

    if (data & SDIO_CCCR_CAP_SMB)
        card->cccr.multi_block = 1;
    if (data & SDIO_CCCR_CAP_LSC)
        card->cccr.low_speed = 1;
    if (data & SDIO_CCCR_CAP_4BLS)
        card->cccr.wide_bus = 1;

    if (cccr_vsn >= SDIO_CCCR_REV_1_10) {
        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_POWER, 0, &data);
        if (ret)
            goto out;

        if (data & SDIO_POWER_SMPC)
            card->cccr.high_power = 1;
    }

    if (cccr_vsn >= SDIO_CCCR_REV_1_20) {
        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
        if (ret)
            goto out;

        card->scr.sda_spec3 = 0;
        card->sw_caps.sd3_bus_mode = 0;
        card->sw_caps.sd3_drv_type = 0;
        if (cccr_vsn >= SDIO_CCCR_REV_3_00 && uhs) {
            card->scr.sda_spec3 = 1;
            ret = mmc_io_rw_direct(card, 0, 0,
                SDIO_CCCR_UHS, 0, &data);
            if (ret)
                goto out;

            if (card->host->caps &
                (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
                 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
                 MMC_CAP_UHS_DDR50)) {
                if (data & SDIO_UHS_DDR50)
                    card->sw_caps.sd3_bus_mode
                        |= SD_MODE_UHS_DDR50;

                if (data & SDIO_UHS_SDR50)
                    card->sw_caps.sd3_bus_mode
                        |= SD_MODE_UHS_SDR50;

                if (data & SDIO_UHS_SDR104)
                    card->sw_caps.sd3_bus_mode
                        |= SD_MODE_UHS_SDR104;
            }

            ret = mmc_io_rw_direct(card, 0, 0,
                SDIO_CCCR_DRIVE_STRENGTH, 0, &data);
            if (ret)
                goto out;

            if (data & SDIO_DRIVE_SDTA)
                card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_A;
            if (data & SDIO_DRIVE_SDTC)
                card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_C;
            if (data & SDIO_DRIVE_SDTD)
                card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_D;
        }

        /* if no uhs mode ensure we check for high speed */
        if (!card->sw_caps.sd3_bus_mode) {
            if (speed & SDIO_SPEED_SHS) {
                card->cccr.high_speed = 1;
                card->sw_caps.hs_max_dtr = 50000000;
            } else {
                card->cccr.high_speed = 0;
                card->sw_caps.hs_max_dtr = 25000000;
            }
        }
    }

out:
    return ret;
}

static int sdio_enable_wide(struct mmc_card *card)
{
    int ret;
    u8 ctrl;

    if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
        return 0;

    if (card->cccr.low_speed && !card->cccr.wide_bus)
        return 0;

    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
    if (ret)
        return ret;

    if ((ctrl & SDIO_BUS_WIDTH_MASK) == SDIO_BUS_WIDTH_RESERVED)
        pr_warning("%s: SDIO_CCCR_IF is invalid: 0x%02x\n",
               mmc_hostname(card->host), ctrl);

    /* set as 4-bit bus width */
    ctrl &= ~SDIO_BUS_WIDTH_MASK;
    ctrl |= SDIO_BUS_WIDTH_4BIT;

    ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
    if (ret)
        return ret;

    return 1;
}

/*
 * If desired, disconnect the pull-up resistor on CD/DAT[3] (pin 1)
 * of the card. This may be required on certain setups of boards,
 * controllers and embedded sdio device which do not need the card's
 * pull-up. As a result, card detection is disabled and power is saved.
 */
static int sdio_disable_cd(struct mmc_card *card)
{
    int ret;
    u8 ctrl;

    if (!mmc_card_disable_cd(card))
        return 0;

    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
    if (ret)
        return ret;

    ctrl |= SDIO_BUS_CD_DISABLE;

    return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
}

/*
 * Devices that remain active during a system suspend are
 * put back into 1-bit mode.
 */
static int sdio_disable_wide(struct mmc_card *card)
{
    int ret;
    u8 ctrl;

    if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
        return 0;

    if (card->cccr.low_speed && !card->cccr.wide_bus)
        return 0;

    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
    if (ret)
        return ret;

    if (!(ctrl & SDIO_BUS_WIDTH_4BIT))
        return 0;

    ctrl &= ~SDIO_BUS_WIDTH_4BIT;
    ctrl |= SDIO_BUS_ASYNC_INT;

    ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
    if (ret)
        return ret;

    mmc_set_bus_width(card->host, MMC_BUS_WIDTH_1);

    return 0;
}


static int sdio_enable_4bit_bus(struct mmc_card *card)
{
    int err;

    if (card->type == MMC_TYPE_SDIO)
        return sdio_enable_wide(card);

    if ((card->host->caps & MMC_CAP_4_BIT_DATA) &&
        (card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
        err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
        if (err)
            return err;
    } else
        return 0;

    err = sdio_enable_wide(card);
    if (err <= 0)
        mmc_app_set_bus_width(card, MMC_BUS_WIDTH_1);

    return err;
}


/*
 * Test if the card supports high-speed mode and, if so, switch to it.
 */
static int mmc_sdio_switch_hs(struct mmc_card *card, int enable)
{
    int ret;
    u8 speed;

    if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
        return 0;

    if (!card->cccr.high_speed)
        return 0;

    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
    if (ret)
        return ret;

    if (enable)
        speed |= SDIO_SPEED_EHS;
    else
        speed &= ~SDIO_SPEED_EHS;

    ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
    if (ret)
        return ret;

    return 1;
}

/*
 * Enable SDIO/combo card's high-speed mode. Return 0/1 if [not]supported.
 */
static int sdio_enable_hs(struct mmc_card *card)
{
    int ret;

    ret = mmc_sdio_switch_hs(card, true);
    if (ret <= 0 || card->type == MMC_TYPE_SDIO)
        return ret;

    ret = mmc_sd_switch_hs(card);
    if (ret <= 0)
        mmc_sdio_switch_hs(card, false);

    return ret;
}

static unsigned mmc_sdio_get_max_clock(struct mmc_card *card)
{
    unsigned max_dtr;

    if (mmc_card_highspeed(card)) {
        /*
         * The SDIO specification doesn't mention how
         * the CIS transfer speed register relates to
         * high-speed, but it seems that 50 MHz is
         * mandatory.
         */
        max_dtr = 50000000;
    } else {
        max_dtr = card->cis.max_dtr;
    }

    if (card->type == MMC_TYPE_SD_COMBO)
        max_dtr = min(max_dtr, mmc_sd_get_max_clock(card));

    return max_dtr;
}

static unsigned char host_drive_to_sdio_drive(int host_strength)
{
    switch (host_strength) {
    case MMC_SET_DRIVER_TYPE_A:
        return SDIO_DTSx_SET_TYPE_A;
    case MMC_SET_DRIVER_TYPE_B:
        return SDIO_DTSx_SET_TYPE_B;
    case MMC_SET_DRIVER_TYPE_C:
        return SDIO_DTSx_SET_TYPE_C;
    case MMC_SET_DRIVER_TYPE_D:
        return SDIO_DTSx_SET_TYPE_D;
    default:
        return SDIO_DTSx_SET_TYPE_B;
    }
}

static void sdio_select_driver_type(struct mmc_card *card)
{
    int host_drv_type = SD_DRIVER_TYPE_B;
    int card_drv_type = SD_DRIVER_TYPE_B;
    int drive_strength;
    unsigned char card_strength;
    int err;

    /*
     * If the host doesn't support any of the Driver Types A,C or D,
     * or there is no board specific handler then default Driver
     * Type B is used.
     */
    if (!(card->host->caps &
        (MMC_CAP_DRIVER_TYPE_A |
         MMC_CAP_DRIVER_TYPE_C |
         MMC_CAP_DRIVER_TYPE_D)))
        return;

    if (!card->host->ops->select_drive_strength)
        return;

    if (card->host->caps & MMC_CAP_DRIVER_TYPE_A)
        host_drv_type |= SD_DRIVER_TYPE_A;

    if (card->host->caps & MMC_CAP_DRIVER_TYPE_C)
        host_drv_type |= SD_DRIVER_TYPE_C;

    if (card->host->caps & MMC_CAP_DRIVER_TYPE_D)
        host_drv_type |= SD_DRIVER_TYPE_D;

    if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_A)
        card_drv_type |= SD_DRIVER_TYPE_A;

    if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_C)
        card_drv_type |= SD_DRIVER_TYPE_C;

    if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_D)
        card_drv_type |= SD_DRIVER_TYPE_D;

    /*
     * The drive strength that the hardware can support
     * depends on the board design.  Pass the appropriate
     * information and let the hardware specific code
     * return what is possible given the options
     */
    drive_strength = card->host->ops->select_drive_strength(
        card->sw_caps.uhs_max_dtr,
        host_drv_type, card_drv_type);

    /* if error just use default for drive strength B */
    err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_DRIVE_STRENGTH, 0,
        &card_strength);
    if (err)
        return;

    card_strength &= ~(SDIO_DRIVE_DTSx_MASK<<SDIO_DRIVE_DTSx_SHIFT);
    card_strength |= host_drive_to_sdio_drive(drive_strength);

    err = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_DRIVE_STRENGTH,
        card_strength, NULL);

    /* if error default to drive strength B */
    if (!err)
        mmc_set_driver_type(card->host, drive_strength);
}


static int sdio_set_bus_speed_mode(struct mmc_card *card)
{
    unsigned int bus_speed, timing;
    int err;
    unsigned char speed;

    /*
     * If the host doesn't support any of the UHS-I modes, fallback on
     * default speed.
     */
    if (!(card->host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
        MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50)))
        return 0;

    bus_speed = SDIO_SPEED_SDR12;
    timing = MMC_TIMING_UHS_SDR12;
    if ((card->host->caps & MMC_CAP_UHS_SDR104) &&
        (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR104)) {
            bus_speed = SDIO_SPEED_SDR104;
            timing = MMC_TIMING_UHS_SDR104;
            card->sw_caps.uhs_max_dtr = UHS_SDR104_MAX_DTR;
    } else if ((card->host->caps & MMC_CAP_UHS_DDR50) &&
           (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_DDR50)) {
            bus_speed = SDIO_SPEED_DDR50;
            timing = MMC_TIMING_UHS_DDR50;
            card->sw_caps.uhs_max_dtr = UHS_DDR50_MAX_DTR;
    } else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
            MMC_CAP_UHS_SDR50)) && (card->sw_caps.sd3_bus_mode &
            SD_MODE_UHS_SDR50)) {
            bus_speed = SDIO_SPEED_SDR50;
            timing = MMC_TIMING_UHS_SDR50;
            card->sw_caps.uhs_max_dtr = UHS_SDR50_MAX_DTR;
    } else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
            MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25)) &&
           (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR25)) {
            bus_speed = SDIO_SPEED_SDR25;
            timing = MMC_TIMING_UHS_SDR25;
            card->sw_caps.uhs_max_dtr = UHS_SDR25_MAX_DTR;
    } else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
            MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25 |
            MMC_CAP_UHS_SDR12)) && (card->sw_caps.sd3_bus_mode &
            SD_MODE_UHS_SDR12)) {
            bus_speed = SDIO_SPEED_SDR12;
            timing = MMC_TIMING_UHS_SDR12;
            card->sw_caps.uhs_max_dtr = UHS_SDR12_MAX_DTR;
    }

    err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
    if (err)
        return err;

    speed &= ~SDIO_SPEED_BSS_MASK;
    speed |= bus_speed;
    err = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
    if (err)
        return err;

    if (bus_speed) {
        mmc_set_timing(card->host, timing);
        mmc_set_clock(card->host, card->sw_caps.uhs_max_dtr);
    }

    return 0;
}

/*
 * UHS-I specific initialization procedure
 */
static int mmc_sdio_init_uhs_card(struct mmc_card *card)
{
    int err;

    if (!card->scr.sda_spec3)
        return 0;

    /*
     * Switch to wider bus (if supported).
     */
    if (card->host->caps & MMC_CAP_4_BIT_DATA) {
        err = sdio_enable_4bit_bus(card);
        if (err > 0) {
            mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
            err = 0;
        }
    }

    /* Set the driver strength for the card */
    sdio_select_driver_type(card);

    /* Set bus speed mode of the card */
    err = sdio_set_bus_speed_mode(card);
    if (err)
        goto out;

    /* Initialize and start re-tuning timer */
    if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning)
        err = card->host->ops->execute_tuning(card->host,
                              MMC_SEND_TUNING_BLOCK);

out:

    return err;
}

/*
 * Handle the detection and initialisation of a card.
 *
 * In the case of a resume, "oldcard" will contain the card
 * we're trying to reinitialise.
 */
static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
                  struct mmc_card *oldcard, int powered_resume)
{
    struct mmc_card *card;
    int err;

    BUG_ON(!host);
    WARN_ON(!host->claimed);

    /*
     * Inform the card of the voltage
     */
    if (!powered_resume) {
        err = mmc_send_io_op_cond(host, host->ocr, &ocr);
        if (err)
            goto err;
    }

    /*
     * For SPI, enable CRC as appropriate.
     */
    if (mmc_host_is_spi(host)) {
        err = mmc_spi_set_crc(host, use_spi_crc);
        if (err)
            goto err;
    }

    /*
     * Allocate card structure.
     */
    card = mmc_alloc_card(host, NULL);
    if (IS_ERR(card)) {
        err = PTR_ERR(card);
        goto err;
    }

    if ((ocr & R4_MEMORY_PRESENT) &&
        mmc_sd_get_cid(host, host->ocr & ocr, card->raw_cid, NULL) == 0) {
        card->type = MMC_TYPE_SD_COMBO;

        if (oldcard && (oldcard->type != MMC_TYPE_SD_COMBO ||
            memcmp(card->raw_cid, oldcard->raw_cid, sizeof(card->raw_cid)) != 0)) {
            mmc_remove_card(card);
            return -ENOENT;
        }
    } else {
        card->type = MMC_TYPE_SDIO;

        if (oldcard && oldcard->type != MMC_TYPE_SDIO) {
            mmc_remove_card(card);
            return -ENOENT;
        }
    }

    /*
     * Call the optional HC's init_card function to handle quirks.
     */
    if (host->ops->init_card)
        host->ops->init_card(host, card);

    /*
     * If the host and card support UHS-I mode request the card
     * to switch to 1.8V signaling level.  No 1.8v signalling if
     * UHS mode is not enabled to maintain compatibility and some
     * systems that claim 1.8v signalling in fact do not support
     * it.
     */
    if ((ocr & R4_18V_PRESENT) &&
        (host->caps &
            (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
             MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
             MMC_CAP_UHS_DDR50))) {
        err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
                true);
        if (err) {
            ocr &= ~R4_18V_PRESENT;
            host->ocr &= ~R4_18V_PRESENT;
        }
        err = 0;
    } else {
        ocr &= ~R4_18V_PRESENT;
        host->ocr &= ~R4_18V_PRESENT;
    }

    /*
     * For native busses:  set card RCA and quit open drain mode.
     */
    if (!powered_resume && !mmc_host_is_spi(host)) {
        err = mmc_send_relative_addr(host, &card->rca);
        if (err)
            goto remove;

        /*
         * Update oldcard with the new RCA received from the SDIO
         * device -- we're doing this so that it's updated in the
         * "card" struct when oldcard overwrites that later.
         */
        if (oldcard)
            oldcard->rca = card->rca;
    }

    /*
     * Read CSD, before selecting the card
     */
    if (!oldcard && card->type == MMC_TYPE_SD_COMBO) {
        err = mmc_sd_get_csd(host, card);
        if (err)
            return err;

        mmc_decode_cid(card);
    }

    /*
     * Select card, as all following commands rely on that.
     */
    if (!powered_resume && !mmc_host_is_spi(host)) {
        err = mmc_select_card(card);
        if (err)
            goto remove;
    }

    if (card->quirks & MMC_QUIRK_NONSTD_SDIO) {
        /*
         * This is non-standard SDIO device, meaning it doesn't
         * have any CIA (Common I/O area) registers present.
         * It's host's responsibility to fill cccr and cis
         * structures in init_card().
         */
        mmc_set_clock(host, card->cis.max_dtr);

        if (card->cccr.high_speed) {
            mmc_card_set_highspeed(card);
            mmc_set_timing(card->host, MMC_TIMING_SD_HS);
        }

        goto finish;
    }

    /*
     * Read the common registers.
     */
    err = sdio_read_cccr(card, ocr);
    if (err)
        goto remove;

    /*
     * Read the common CIS tuples.
     */
    err = sdio_read_common_cis(card);
    if (err)
        goto remove;

    if (oldcard) {
        int same = (card->cis.vendor == oldcard->cis.vendor &&
                card->cis.device == oldcard->cis.device);
        mmc_remove_card(card);
        if (!same)
            return -ENOENT;

        card = oldcard;
    }
    mmc_fixup_device(card, NULL);

    if (card->type == MMC_TYPE_SD_COMBO) {
        err = mmc_sd_setup_card(host, card, oldcard != NULL);
        /* handle as SDIO-only card if memory init failed */
        if (err) {
            mmc_go_idle(host);
            if (mmc_host_is_spi(host))
                /* should not fail, as it worked previously */
                mmc_spi_set_crc(host, use_spi_crc);
            card->type = MMC_TYPE_SDIO;
        } else
            card->dev.type = &sd_type;
    }

    /*
     * If needed, disconnect card detection pull-up resistor.
     */
    err = sdio_disable_cd(card);
    if (err)
        goto remove;

    /* Initialization sequence for UHS-I cards */
    /* Only if card supports 1.8v and UHS signaling */
    if ((ocr & R4_18V_PRESENT) && card->sw_caps.sd3_bus_mode) {
        err = mmc_sdio_init_uhs_card(card);
        if (err)
            goto remove;

        /* Card is an ultra-high-speed card */
        mmc_card_set_uhs(card);
    } else {
        /*
         * Switch to high-speed (if supported).
         */
        err = sdio_enable_hs(card);
        if (err > 0)
            mmc_sd_go_highspeed(card);
        else if (err)
            goto remove;

        /*
         * Change to the card's maximum speed.
         */
        mmc_set_clock(host, mmc_sdio_get_max_clock(card));

        /*
         * Switch to wider bus (if supported).
         */
        err = sdio_enable_4bit_bus(card);
        if (err > 0)
            mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
        else if (err)
            goto remove;
    }
finish:
    if (!oldcard)
        host->card = card;
    return 0;

remove:
    if (!oldcard)
        mmc_remove_card(card);

err:
    return err;
}

/*
 * Host is being removed. Free up the current card.
 */
static void mmc_sdio_remove(struct mmc_host *host)
{
    int i;

    BUG_ON(!host);
    BUG_ON(!host->card);

    for (i = 0;i < host->card->sdio_funcs;i++) {
        if (host->card->sdio_func[i]) {
            sdio_remove_func(host->card->sdio_func[i]);
            host->card->sdio_func[i] = NULL;
        }
    }

    mmc_remove_card(host->card);
    host->card = NULL;
}

/*
 * Card detection - card is alive.
 */
static int mmc_sdio_alive(struct mmc_host *host)
{
    return mmc_select_card(host->card);
}

/*
 * Card detection callback from host.
 */
static void mmc_sdio_detect(struct mmc_host *host)
{
    int err;

    BUG_ON(!host);
    BUG_ON(!host->card);

    /* Make sure card is powered before detecting it */
    if (host->caps & MMC_CAP_POWER_OFF_CARD) {
        err = pm_runtime_get_sync(&host->card->dev);
        if (err < 0)
            goto out;
    }

    mmc_claim_host(host);

    /*
     * Just check if our card has been removed.
     */
    err = _mmc_detect_card_removed(host);

    mmc_release_host(host);

    /*
     * Tell PM core it's OK to power off the card now.
     *
     * The _sync variant is used in order to ensure that the card
     * is left powered off in case an error occurred, and the card
     * is going to be removed.
     *
     * Since there is no specific reason to believe a new user
     * is about to show up at this point, the _sync variant is
     * desirable anyway.
     */
    if (host->caps & MMC_CAP_POWER_OFF_CARD)
        pm_runtime_put_sync(&host->card->dev);

out:
    if (err) {
        mmc_sdio_remove(host);

        mmc_claim_host(host);
        mmc_detach_bus(host);
        mmc_power_off(host);
        mmc_release_host(host);
    }
}

/*
 * SDIO suspend.  We need to suspend all functions separately.
 * Therefore all registered functions must have drivers with suspend
 * and resume methods.  Failing that we simply remove the whole card.
 */
static int mmc_sdio_suspend(struct mmc_host *host)
{
    int i, err = 0;

    for (i = 0; i < host->card->sdio_funcs; i++) {
        struct sdio_func *func = host->card->sdio_func[i];
        if (func && sdio_func_present(func) && func->dev.driver) {
            const struct dev_pm_ops *pmops = func->dev.driver->pm;
            if (!pmops || !pmops->suspend || !pmops->resume) {
                /* force removal of entire card in that case */
                err = -ENOSYS;
            } else
                err = pmops->suspend(&func->dev);
            if (err)
                break;
        }
    }
    while (err && --i >= 0) {
        struct sdio_func *func = host->card->sdio_func[i];
        if (func && sdio_func_present(func) && func->dev.driver) {
            const struct dev_pm_ops *pmops = func->dev.driver->pm;
            pmops->resume(&func->dev);
        }
    }

    if (!err && mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
        mmc_claim_host(host);
        sdio_disable_wide(host->card);
        mmc_release_host(host);
    }

    return err;
}

static int mmc_sdio_resume(struct mmc_host *host)
{
    int i, err = 0;

    BUG_ON(!host);
    BUG_ON(!host->card);

    /* Basic card reinitialization. */
    mmc_claim_host(host);

    /* No need to reinitialize powered-resumed nonremovable cards */
    if (mmc_card_is_removable(host) || !mmc_card_keep_power(host))
        err = mmc_sdio_init_card(host, host->ocr, host->card,
                    mmc_card_keep_power(host));
    else if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
        /* We may have switched to 1-bit mode during suspend */
        err = sdio_enable_4bit_bus(host->card);
        if (err > 0) {
            mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
            err = 0;
        }
    }

    if (!err && host->sdio_irqs)
        wake_up_process(host->sdio_irq_thread);
    mmc_release_host(host);

    /*
     * If the card looked to be the same as before suspending, then
     * we proceed to resume all card functions.  If one of them returns
     * an error then we simply return that error to the core and the
     * card will be redetected as new.  It is the responsibility of
     * the function driver to perform further tests with the extra
     * knowledge it has of the card to confirm the card is indeed the
     * same as before suspending (same MAC address for network cards,
     * etc.) and return an error otherwise.
     */
    for (i = 0; !err && i < host->card->sdio_funcs; i++) {
        struct sdio_func *func = host->card->sdio_func[i];
        if (func && sdio_func_present(func) && func->dev.driver) {
            const struct dev_pm_ops *pmops = func->dev.driver->pm;
            err = pmops->resume(&func->dev);
        }
    }

    return err;
}

static int mmc_sdio_power_restore(struct mmc_host *host)
{
    int ret;
    u32 ocr;

    BUG_ON(!host);
    BUG_ON(!host->card);

    mmc_claim_host(host);

    /*
     * Reset the card by performing the same steps that are taken by
     * mmc_rescan_try_freq() and mmc_attach_sdio() during a "normal" probe.
     *
     * sdio_reset() is technically not needed. Having just powered up the
     * hardware, it should already be in reset state. However, some
     * platforms (such as SD8686 on OLPC) do not instantly cut power,
     * meaning that a reset is required when restoring power soon after
     * powering off. It is harmless in other cases.
     *
     * The CMD5 reset (mmc_send_io_op_cond()), according to the SDIO spec,
     * is not necessary for non-removable cards. However, it is required
     * for OLPC SD8686 (which expects a [CMD5,5,3,7] init sequence), and
     * harmless in other situations.
     *
     * With these steps taken, mmc_select_voltage() is also required to
     * restore the correct voltage setting of the card.
     */

    sdio_reset(host);
    mmc_go_idle(host);
    mmc_send_if_cond(host, host->ocr_avail);

    ret = mmc_send_io_op_cond(host, 0, &ocr);
    if (ret)
        goto out;

    if (host->ocr_avail_sdio)
        host->ocr_avail = host->ocr_avail_sdio;

    host->ocr = mmc_select_voltage(host, ocr & ~0x7F);
    if (!host->ocr) {
        ret = -EINVAL;
        goto out;
    }

    ret = mmc_sdio_init_card(host, host->ocr, host->card,
                mmc_card_keep_power(host));
    if (!ret && host->sdio_irqs)
        mmc_signal_sdio_irq(host);

out:
    mmc_release_host(host);

    return ret;
}

static const struct mmc_bus_ops mmc_sdio_ops = {
    .remove = mmc_sdio_remove,
    .detect = mmc_sdio_detect,
    .suspend = mmc_sdio_suspend,
    .resume = mmc_sdio_resume,
    .power_restore = mmc_sdio_power_restore,
    .alive = mmc_sdio_alive,
};


/*
 * Starting point for SDIO card init.
 */
int mmc_attach_sdio(struct mmc_host *host)
{
    int err, i, funcs;
    u32 ocr;
    struct mmc_card *card;

    BUG_ON(!host);
    WARN_ON(!host->claimed);

    err = mmc_send_io_op_cond(host, 0, &ocr);
    if (err)
        return err;

    mmc_attach_bus(host, &mmc_sdio_ops);
    if (host->ocr_avail_sdio)
        host->ocr_avail = host->ocr_avail_sdio;

    /*
     * Sanity check the voltages that the card claims to
     * support.
     */
    if (ocr & 0x7F) {
        pr_warning("%s: card claims to support voltages "
               "below the defined range. These will be ignored.\n",
               mmc_hostname(host));
        ocr &= ~0x7F;
    }

    host->ocr = mmc_select_voltage(host, ocr);

    /*
     * Can we support the voltage(s) of the card(s)?
     */
    if (!host->ocr) {
        err = -EINVAL;
        goto err;
    }

    /*
     * Detect and init the card.
     */
    err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
    if (err) {
        if (err == -EAGAIN) {
            /*
             * Retry initialization with S18R set to 0.
             */
            host->ocr &= ~R4_18V_PRESENT;
            err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
        }
        if (err)
            goto err;
    }
    card = host->card;

    /*
     * Enable runtime PM only if supported by host+card+board
     */
    if (host->caps & MMC_CAP_POWER_OFF_CARD) {
        /*
         * Let runtime PM core know our card is active
         */
        err = pm_runtime_set_active(&card->dev);
        if (err)
            goto remove;

        /*
         * Enable runtime PM for this card
         */
        pm_runtime_enable(&card->dev);
    }

    /*
     * The number of functions on the card is encoded inside
     * the ocr.
     */
    funcs = (ocr & 0x70000000) >> 28;
    card->sdio_funcs = 0;

    /*
     * Initialize (but don't add) all present functions.
     */
    for (i = 0; i < funcs; i++, card->sdio_funcs++) {
        err = sdio_init_func(host->card, i + 1);
        if (err)
            goto remove;

        /*
         * Enable Runtime PM for this func (if supported)
         */
        if (host->caps & MMC_CAP_POWER_OFF_CARD)
            pm_runtime_enable(&card->sdio_func[i]->dev);
    }

    /*
     * First add the card to the driver model...
     */
    mmc_release_host(host);
    err = mmc_add_card(host->card);
    if (err)
        goto remove_added;

    /*
     * ...then the SDIO functions.
     */
    for (i = 0;i < funcs;i++) {
        err = sdio_add_func(host->card->sdio_func[i]);
        if (err)
            goto remove_added;
    }

    mmc_claim_host(host);
    return 0;


remove_added:
    /* Remove without lock if the device has been added. */
    mmc_sdio_remove(host);
    mmc_claim_host(host);
remove:
    /* And with lock if it hasn't been added. */
    mmc_release_host(host);
    if (host->card)
        mmc_sdio_remove(host);
    mmc_claim_host(host);
err:
    mmc_detach_bus(host);

    pr_err("%s: error %d whilst initialising SDIO card\n",
        mmc_hostname(host), err);

    return err;
}